Tuned antenna system



Oct. 11, 1938. J. R. RIGANDI TUNED ANTENNA SYSTEM Filed Oct. 19, 1936 s &9 97

Q Q Q o o 0 0 0 0 ATTORNEY5 Patented Oct. 11, 1938 umrsoqsrA-res PATENT OFFICE TUNED ANTENNA SYSTEM Joseph Ruig Rlgandi, WesterleiglnN. Y. Application October 19, 1936, Serial No. 106,281 I 7 Claims.

This "invention relates tone w and useful improvements in radio apparatus and more particularly it pertains to antenna systems therefor, and this application is a continuation in. part of prior application filed November 30, 1934, Serial Number .755,3'76, Patent No. 2,058,037, dated'wOctober 20, 1936.

.It, is one object of the present invention to 7 provide a new and improved form of antenna 1 which -is capable of adjustment and tuning to meet local requirements and particular set conditions. c

, It is a' further object of the invention to provide a new and improved antenna system which will materially simplify tuning. and improve rereception andoperationof radio receiving sets.

With the above and other objects in view, reference will be had to the accompanying drawing, in which: 7

Figural is .a diagrammatic view illustrating an antennaconstructed in accordancewith the present invention, g 7 c Figure 2 is a diagrammatic view illustrating a modified form of the invention,

Figure 3 is a diagrammatic view illustrating a further modified form of the invention,

Figure 4 is a diagrammatic view illustrating, a further modified formof the invention, and;

Figure 5 is a similar view illustrating a still further modified form of the invention.

Referring in detail to the drawing and particularly to Figure 1, A designates an induction coil which consists of a primary winding l0 and a secondary winding H. The primary winding forms a continuation of the antenna wire or its lead-in which is herein designated l2. Leading from one end of the secondary winding ll there is a conductor I3 which is electrically connected, as at I4, to the movable member [50f a variable resistance l6. Interposed in the conductor l3 thereis a variable condenser 16 and it will be noted that one end of the primary .winding In of the induction coil A is electrically connected as at I! to the conductor I3 at a point beyond the variable condenser IB. Leading from the secondary winding ll of the induction coil A, there is a conductor I8 which is connected as at l9 to the ground post of a radio receiver designated 20. The variable 50 resistance heretoforementioned is connected at one of its ends to the antenna post of the receiver 20, the other end being connected to the ground and interposed between the variable resistance and the ground, there is a fixed condenser 2|.

55' From the foregoing it will be apparent that the variable condenser I6 will serve to tune the antenna circuit to the proper frequency of the receiver and will also actto vary the volume of the set. Furthermore, the .volume may also be controlled by operation of the movable member I5 of the variable resistance I6.

In Figure 2, the reference character designates an outside antenna, the lead of which is connected to a switch 3| by means of, which the antenna may be connected or disconnected with one end of the primary winding 32 of an induction coil. B. The reference numeral 33 designates the secondary winding of the induction coil B and one end of this secondary winding 33 is connected as at 34 to a conductor 35 leading from the opposite end of the primary winding 32, and interposed between the secondary winding 33 and the point 34 where it is connected to the primary winding 32, there is a variable condenser .36. Leading from the secondary winding 33 there is a conductor 31 which is connected as at 38 to the movable member 39 of a variable resistance 40. The conductor-35 is connected as at 4| to. the ground side of the primary winding 42 of the tube circuit, the secondary winding of this tube circuit being designated 43. The reference character 44 designates a fixed condenser which is electrically. connected to the variable resistance and leading from the fixed condenser 44 and electrically connected as at 4| to the ground side 30 of the primary winding 42 of the tube circuit, there is a conductor 45'which is electrically connectedas-at and 41 to the secondary winding 43 of thetube circuit. Interposed between the r two points of connection 46 and 41 there is a variable condenser 48 and in said conductor 45, there is a fixed condenser 49.

In Figure 3, the reference character G designates an induction coil of which 50 .is the primary winding, the secondary winding being designated 5|. leading from one end of the winding 5| there is a conductor 52 connected as at 53 to the-ground and also to the ground side of the winding H as at 54. The opposite end of the secondary winding 5| has an extension conductor 55 which is connected as at 56 to the primary winding 50 and by the conductor 51 to a conductor 58 which includes the resistance element 59 of a variable resistanca'which is also connected to 5 ground .at 53. The movable element SI of the variable resistance is connected by a conductor 62 to'the grid 63 of the tube of the first stage of radio; frequency.

1 InFigure 4 I have illustrated a further modi- 55 switch v15 included in this conductor 12.

fied form of the invention in which there are two antennae employed. The antennae are designated 10 and H. The antenna 10 is connected by a suitable lead I2 to the primary winding 13 of an induction coil 14, and there is a The other end of the primary winding 13 is connected as at 16 to a conductor 11, which in turn :is connected to one end of the secondary winding'18 of said induction coil 14, and in this conductor there is'interposed a variable condenser 19. The other end of the secondary winding of the in= duction coil 14 is connected by means of a con-, ductor 30 to a mid-tap 8| in the primary Wind'- conductor includes a'variabie condenser 90'.

The opposite end of the said secondary winding 85 is connected by a conductor 9I to the movable member 92 of a switch, which movable member is adapted for engagement with a contact 93 from which leads a conductor 94. Leading from the conductor 94 to ground there is a conductor 96 and the resistance element 91 is connected to this conductor 96 as at 98. Leading from the oppo-o site end of the resistance element 91 there is a conductor 99, which is connected to the grid 00 of the first stage of radio frequency of a receiving set. Connected to the conductor 95 as at iI there is a lead I02 which is connected to the primary Winding I03 of an induction coil I04 and the other terminal of said primary winding I03 is connected by a conductor I05 to a conductor I06 leading from the secondary winding I01 of the induction coil I04, and this conductor I05 includes a variable condenser I I0, The opposite end of the secondary winding of the induction coil I04 is connected as at III to the conductor 99, heretofore mentioned.

By this arrangement it will be apparent that either of the induction coils 14 or 83 may be ineluded, in the antenna circuit, or both may be included, or both may be excluded from the antenna circuit. Furthermore, by reason of the fact that the windings of each of the induction coils are electrically coupled, the incoming signal energy of these coils may be varied by the variable condensers in the circuit of each coil.

In Figure 5 I have shown a still further modified form of the invention in which I20 designates an antenna from which extends a lead in IEI. The lead in includes a switch I22 and is connected to the primary winding I23 of an induction coil I24. Leading from the opposite end of the primary winding I23 there is a conductor I25, and this conductor 'i25 is connected as at I26 to the primary winding I21 of an induction coil I28, the connection being made substantially mid-way between the end turns of said winding. The reference numeral I30 designates the secondary winding of the induction coil I24, and extending from one end thereof, there is a conductor I3I which is connected nLid-way between the ends of the secondary winding I32 of the induction coil I28. The opposite end of the winding I30 of the induction coil I24 is connected by means of a conductor I35 to the conductor I25 as at I36, and this conductor I35 includes a variable condenser I31. Leading from one end of the secondary winding I32 of the induction coil I28 there is a conductor I39 which is connected to the movable member I40 of a variable resistance I4 I, and one end of the primary winding I21 of the induction coil I28 is connected with this conductor I39 as at MI, by means of a suitable lead I42. The opposite end of the primary winding I21 is connectedto ground by means of a conductor I43. The opposite end to that heretofore mentioned of the secondary winding I32 of the induction coil 128 is connected by means of conductors I44 and I45 to the resistance element I46 oi the variable resistance, and a fixed condenser I41 is interposed in this conductor. In this form of the invention the reference numeral I50 designates the first stage of radio frequency of a conventional receiving circuit and leading from the grid thereof there is a conductor I5I which is connected to a conductor I52 having a movable switch element I53. This movable switch element I53 is adapted to contact with one of a plurality of points I54, I55, I55 and I51, and these points are tapped upon a coil or winding, I58. The fixed element I46 of the variable resistance is connected by a conductor I60 to the contact point I51, and the fixed element of the variable resistance, heretofore mentioned, is connected in shunt with'the winding L. I

From the foregoing it will be apparent that the present invention provides in various modi-' fied forms, a tuned antenna circuit in which clearer signals, reduced interference, and greater volume is obtained, and that in its broadest aspect these results are accomplished by reason of the fact that said antenna circuit includes one or more induction coils together with means for tuning the signal energy in each'oi the windings of said coils, and while the invention has been herein disclosed in its preferred forms I do not wish to be specifically limited to the specific constructions illustrated since the invention may be carried out in other forms within the scope of the appended claims. 7

Having thus described the invention, what is claimed as new, is:

1. An antenna circuit adapted to bebuilt into a conventional radio receiving circuit, said antenna circuit including an inductance coil, having a primary and. secondary winding a variable condenser electrically connected to both the primary and secondary winding and a variable resistance, a fixed condenser in series with said variable resistance, a connection connecting said variable resistance'in shunt with the input of the first tube of a conventional receiver circuit and variably connected to both the primary and secondary winding of the inductance coil, an exterior antenna wire, a switch for connecting and disconnecting said antenna wire to the primary winding of the inductance coil.

2. A double antenna circuit comprising in combination with a conventional radio receiver and its first vacuum tube stage, two antenna circuits each antenna circuit including an inductance coil, each of which coils includes a primary and a secondary winding, a variable condenser included in each antenna circuit for tuning the signal energy of the circuit, each of said variable condensers being connected to the primary and secondary winding of its respective'inductance coil, means for controlling the volume before the signal reaches the first vacuum tube stage of the said conventional radio receiver, said means including a variable resistance, said variable resistance being connected to the primary and the secondary windings of the antenna circuit, a plurality of antennae, and means for electrically connecting and disconnecting said antennae to one side lead of each primary winding.

3. A double tuning antenna circuit including two inductance coils, each having a primary and secondary winding the primary and secondary windings of one of said inductance coils being electrically connected respectively with the primary and secondary windings of the other of said inductance coils at a point intermediate of the ends of said windings, and means for varying the signal energy of each inductance coil, said last mentioned means including a variable condenser electrically connected on one side to the primary windings of both of said inductance coils and upon the other side to the secondary windings of both of said inductance coils.

4. In combination with a radio receiving circuit employing vacuum tubes, an antenna system including an antenna, an inductive coupling for connecting the antenna to the said receiving set, said iductive coupling including an inductance coil, including a primary and secondary winding a variable condenser connected to one lead of the primary winding of said inductance coil and to one lead of the secondary winding of the inductance coil, and means for electrically connecting the other lead of the primary winding of the inductance coil to the grid circuit of the first vacuum tube of the radio receiving circuit, means for connecting the other lead of the secondary winding of said induction coil to the ground circuit of the radio receiving circuit, and a variable resistance interposed between the antenna system and the said receiving circuit.

5. An antenna system comprising in combination with a radio receiving circuit including a vacuum tube, an inductance coil and a variable condenser, said antenna system comprising an inductance coil, including a primary and secondary winding a variable condenser connected to both the primary and secondary winding of the inductance coil, and means for connecting the antenna system to the receiving circuit, said means comprising a variable resistance electrically connected to and interposed between the inductance coil of the receiver and the inductance coil of the antenna system.

6. In an antenna system, an antenna, an inductance coil, including a primary and secondary Winding means for connecting one of the leads of the primary winding of said inductance coil to said antenna, a variable condenser connected to one lead of the primary winding and to one lead of the secondary winding of said inductance coil, a variable resistance connected in series to the inductance coil and connected in shunt to the variable condenser, said variable resistance being variably connected to one lead of the primary winding and to one lead of the secondary winding of said inductance coil, a vacuum tube radio frequency amplification circuit, said vacuum tube circuit including an inductance coil, a variable condenser shunt connected to the secondary winding of said second mentioned inductance coil, a condenser connected to one side of the primary and to one side of the secondary winding of said second mentioned inductance coil, and means for connecting the antenna system to the primary winding of the inductance coil of the vacuum tube circuit, said means including said variable resistance.

7. In an antenna system, including double antenna wires, two inductance coils, each of said inductance coils having a primary and a secondary winding, the primary and secondary winding of one of said inductance coils having electrical connection with the primary and secondary winding of the other inductance coil, a variable condenser for each of said inductance coils, a variable resistance including a series condenser variably connected to one lead of the primary and to one lead of the secondary of one of said inductance coils, a vacuum tube radio frequency amplification circuit, said vacuum tube circuit including an inductance coil, a variable condenser shunting said inductance coil, and means for connecting the antenna system to the inductance coil of the vacuum tube circuit, said means including said afore-mentioned variable resistance shunt connected to the inductance coil of the vacuum tube circuit, and a switch for each of said first mentioned inductance coils for connecting and disconnecting said double antenna wires with said first mentioned inductance coils.

JOSEPH RUIG RIGANDI. 

